The invention relates to a strip chart recorder, and more particularly to a thermographic device for the recording of medical data.
When monitoring vital functions of a human being such as heart or brain induced electrical signals, it is frequently important to record other data pertinent to the patient. Rather prosaic but nonetheless important is identification indicia.
U.S. Pat. No. 3,754,279 issued on Aug. 21, 1973 to Valenti et al discloses a thermal recorder designed to accomplish this purpose. It describes a thermographic recorder incorporating, in addition to the normal galvanometrically driven thermal stylus for indicating analog body function, a thermal printout head for recording numeric characters.
In prior art devices the thermal printout head (TPH) is located on a viewing platen remotely of the stylus and is used to note pertinent but exogenous medical data, mainly relating to patient identification. Recorders of this design do have significant disadvantages and introduce limitations. Placement of the TPH on the platen obscures observation of the recorded data by medical personnel and both esthetically and structurally encumbers the frontal aspect of the unit.
More importantly, prior art location of TPH renders practically impossible the real time recording of digital data in time registration with recorded analog functions. Hence, prior art print head devices are practically limited to the recording of information extrinsic to the body function of the individual being observed.